Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Real Estate [Abstract]
Land and land improvements	$ 1,101,475	$ 1,094,470
Building and improvements	4,531,773	4,501,921
Less accumulated depreciation	(967,251)	(940,115)
Operating real estate	4,665,997	4,656,276
Development in progress	321,331	267,450
Land held for development	345,632	336,569
Net real estate	5,332,960	5,260,295
Cash and cash equivalents	36,535	43,642
Restricted cash	10,680	12,383
Accounts receivable	14,998	13,994
Deferred rent receivable	114,811	109,245
Deferred financing and leasing costs, net of accumulated amortization (March 31, 2017, $156,509; December 31, 2016, $152,309)	155,105	153,393
Investments in and advances to unconsolidated joint ventures	254,864	245,078
Assets held for sale	5,039	4,548
Prepaid expenses and other assets	158,909	150,235
Total assets	6,083,901	5,992,813
LIABILITIES
Mortgage loans	274,260	276,650
Unsecured notes	2,280,970	2,280,286
Credit facility	115,000	0
Accounts payable	56,357	65,914
Accrued interest	34,850	21,878
Dividend and distributions payable	60,293	71,501
Other liabilities	199,718	206,124
Total liabilities	3,021,448	2,922,353
Noncontrolling interest - operating partnership - 301,483 preferred units outstanding as of March 31, 2017 and December 31, 2016	7,537	7,537
EQUITY
Common shares of beneficial interest, $.001 par value, 283,987,000 shares authorized; 147,203,022 and 146,993,018 shares issued and outstanding as of March 31, 2017 and December 31, 2016, respectively	147	147
Additional paid-in capital	3,660,740	3,655,910
Accumulated other comprehensive loss	(52,622)	(56,031)
Distributions in excess of net income	(612,424)	(596,635)
Total Liberty Property Trust shareholders' equity	2,995,841	3,003,391
Noncontrolling interest - operating partnership
Noncontrolling interest - operating partnerships	54,174	54,631
Noncontrolling interest - consolidated joint ventures	4,901	4,901
Total owners' equity	3,054,916	3,062,923
Total liabilities, noncontrolling interest - operating partnership and equity	6,083,901	5,992,813
Liberty Property Limited Partnership [Member]
Real Estate [Abstract]
Land and land improvements	1,101,475	1,094,470
Building and improvements	4,531,773	4,501,921
Less accumulated depreciation	(967,251)	(940,115)
Operating real estate	4,665,997	4,656,276
Development in progress	321,331	267,450
Land held for development	345,632	336,569
Net real estate	5,332,960	5,260,295
Cash and cash equivalents	36,535	43,642
Restricted cash	10,680	12,383
Accounts receivable	14,998	13,994
Deferred rent receivable	114,811	109,245
Deferred financing and leasing costs, net of accumulated amortization (March 31, 2017, $156,509; December 31, 2016, $152,309)	155,105	153,393
Investments in and advances to unconsolidated joint ventures	254,864	245,078
Assets held for sale	5,039	4,548
Prepaid expenses and other assets	158,909	150,235
Total assets	6,083,901	5,992,813
LIABILITIES
Mortgage loans	274,260	276,650
Unsecured notes	2,280,970	2,280,286
Credit facility	115,000	0
Accounts payable	56,357	65,914
Accrued interest	34,850	21,878
Dividend and distributions payable	60,293	71,501
Other liabilities	199,718	206,124
Total liabilities	3,021,448	2,922,353
Noncontrolling interest - operating partnership - 301,483 preferred units outstanding as of March 31, 2017 and December 31, 2016	7,537	7,537
EQUITY
General partner’s equity - 147,203,022 and 146,993,018 common units outstanding as of March 31, 2017 and December 31, 2016, respectively	2,995,841	3,003,391
Limited partners' equity	54,174	54,631
Noncontrolling interest - operating partnership
Noncontrolling interest - consolidated joint ventures	4,901	4,901
Total owners' equity	3,054,916	3,062,923
Total liabilities, noncontrolling interest - operating partnership and equity	$ 6,083,901	$ 5,992,813